This application addresses broad Challenge Area (04) Clinical Research and the specific Challenge Topic, 04-CA-111: Quality of Cancer Surgery and Outcomes. This application also has specific relevance to broad challenge area (05) Comparative Effectiveness Research and specific Challenge Topic 05-CA-104: Comparative Effectiveness Research on Cancer Treatment. Despite the frequency of breast cancer surgery worldwide, there remains a paucity of data for surgical outcomes discernable at the surgeon or hospital level. Recent measures of surgical quality have been proposed for breast cancer surgery. This application seeks to combine the expertise of the University of Vermont in cancer surgery outcomes assessment with expertise of the Cancer Research Network (CRN), a network of investigators at the forefront of cancer-related effectiveness research. There is currently no available healthcare administrative database which will allow comparative effectiveness research of initial breast cancer surgery, as existing databases lack the specificity and detail of critical data elements that currently drive decisions for initial breast surgery We propose to develop a multicenter electronic breast cancer surgery outcomes database that will allow for an assessment of measures of surgical quality by examining variation in outcomes of initial breast cancer surgery. In addition, we will develop protocols and data capture tools that can be implemented elsewhere in order to extend this data network to future additional CRN sites. The development of such a clinical data network will allow comparative effectiveness research to be conducted, particularly as related to current controversies in the management of breast cancer, such as an appropriate pathologic margin of clearance in partial mastectomies. We believe this controversy currently results in tens of thousands of additional operations performed annually, lowering patient quality of life and at the cost of hundreds of millions of dollars, without specified impact on cancer recurrence or patient survival. Our development of a well designed cancer surgery outcomes database will allow for important clinical questions to be answered in a timely and cost-effective manner. PUBLIC HEALTH RELEVANCE: This application seeks to firmly establish measures of quality for initial breast cancer surgery. Improved understanding of surgical quality can potentially diminish wide variability in outcomes and healthcare costs associated with breast cancer surgery.